(Redeemed invasion, Redeemed invasion!)
I did a ton of research prior to speccing out an Alienware M17X, specifically built for WoW. Research said that:
1) While WoW has been tweaked over the years to allow some multi-core, multi-thread use, the program is basically one giant thread, one minor thread, and then a bunch if minuscule threads. So a fast clock-speed, low-core processor gets better results than a quad core. Desktop performance quad cores tend to deliver both so it's not really a tradeoff, but mobile quad cores tend to be slower, so not a good WoW choice. Tools like hyperthreading and turbo-boost aren't ideal for WoW, although if you hard-set the turboboost in then that is equivalent to the faster clock speed. Although it's effectively turning a quad-core into a dual-core machine. WoW is highly processor dependent, low FPS in places like Dalaran is more likely to be processor driven then graphics card drive.
2) Having at least 2GB of memory helps WoW, but havign a lot more than 2GB doesn't change that much
3) Hard drive speed matters a lot. I can vouch for the power of the SSD. I recently moved to an Intel SSD and, especially since the 4.0.3a, zone-in times are crazy-fast ... a few seconds at most.
4) Graphics cards matter, but not as much as most games. If you have any sort of vaguely modern card, it can handle high settings.
5) System requirements for across the board LOW settings for WoW would probably work on a lawnmore. But across the board EXTREME settings are relatively demanding.
Anyhow, I'm sure not everything I've said above is without controversy, but it's what I came up with. I can definitely say that the SSD rocks.
Specifically on the mouse topic ... it's an amusing topic. I think it's funny that thier "lowest end" system has a $35 mouse and the "highest end" has a $40 mouse. They shoulda at least recommended a Naga or something. I am a fan of Razer mice ... I love the texture and they fit my hand right. But mice are extremely personal/hand dependent. I'm surprised that high-end mice aren't made in small/medium/large sizes. Recommending a specific mouse in a system build is kinda giggle-worthy.